Outcomes
The main objective of the study is to decrease SB and increase PA among the mothers and their children by means of the movement-to-music video program.
The primary outcomes of the study are SB and PA, which will be assessed objectively by means of the accelerometer and further examined via the exercise diaries and questionnaires. Measurements will be performed in the first, second and eighth weeks of the intervention. For inclusion in the analysis, accelerometer data for at least four days per week and measurement time of more than 10 h per day will be needed. Participants using the accelerometer on fewer than four days per week will be excluded. Any participants whose measurement time for a given day is over 20 h will be considered to have slept with the accelerometer. To avoid possible bias in SB time, the recording time for them will be capped at 20 h, with the deduction coming from their lying-down time. The measurement discriminates among the time spent in a sitting or reclining posture, standing still, and PA. The daily amount of standing-up (breaks in sedentary time) will be calculated from the number of lying/sitting periods that end with standing. Lying, sitting, and standing time, along with light, moderate, and vigorous PA time during waking hours, will be analyzed both in minutes and as a proportion of the measurement time (at least 10 h per day). In the analysis, moderate and vigorous activity might be combined as MVPA if vigorous PA covers a very small proportion of the total measurement time.
Secondary outcomes of the study include the quantity of self-reported sitting and screen time among mothers and children, motivation to exercise, and the motivational quality of the music and movement-to-music video. Additional secondary outcomes are mother’s weight and quality of life, depression, anxiety, perceived health, and work ability assessed by a questionnaire.
The specific aim is to study the effectiveness of the intervention by comparing accelerometer use alone with a combination of accelerometer and movement-to-music video program for mother-child pairs.
Accelerometer measures and pre-test
The main aim with the project is to reduce sedentariness among mothers and their children. The accelerometers continuously measures tri-axial acceleration caused by any movement and permit precise assessment of individuals’ PA and SB both. Data on PA and SB will be collected in raw mode via a tri-axial accelerometer (Hookie AM 20, Traxmeet Ltd, of Espoo, Finland). The data will be analyzed as the mean signal amplitude deviation (MAD) of resultant acceleration for each epoch [
21]. The choice of algorithms for use in the study is based on pilot studies conducted at the UKK Institute.
The resultant, which indicates the magnitude of the acceleration, is calculated for every measured sample. It is possible to determine with high accuracy whether the participant is standing, sitting, or lying down by applying the information from the three measurement axes of the accelerometer. Walking is used as a reference. While the body orientation during walking is upright and the direction of Earth’s gravity vector is constant, the vertical position (angle) of the accelerometer can be identified during normal walking. This known position (i.e., the angle of the accelerometer) can then be compared to other positions for purposes of recognizing different body postures. The number of instances of standing-up can be calculated from the number of lying/sitting periods ending with a clear vertical acceleration. In standardized conditions, standing can be distinguished from sitting or lying with 100 % accuracy, and sitting from lying with 95 % accuracy [Vähä-Ypyä et al., unpublished manuscript].
PA will be divided into three intensity categories by metabolic equivalent (MET): light, moderate, and vigorous. The classification was validated with simultaneous measurements of acceleration and oxygen consumption [
30]. Light PA has been defined as activity corresponding to 1.5–2.9 METs, moderate activity as 3.0–5.9 METs and vigorous activity more than 6 METs [
4,
5,
30].
Accelerometers were pre-tested with eleven 2–9-year-old children. The children engaged in free movement, play, and games on a test track field for one hour for determination of how scurrying-type movements appear in the readings. Another test, on a running track, tested speeds ranging from slow walking to participants’ maximum rate of running. In addition, accelerometers were piloted in free-living conditions with 10 children aged 4–7 for one week. In these tests, the acceleration signal behaved as expected, in other words, the MAD-value was higher for younger (smaller) children at the same speed and different activity intensities could be identified from the data.
The movement-to-music DVD’s production and pre-testing
In spring 2014, three distinct movement-to-music video programs were prepared, by the Sibelius-Academy music-education students in course specifically on children’s music programs. The music was composed and arranged with lyrics. Further video programs were produced for the study specifically as part of a training course on children’s music and videos. Two of the videos last about 10 min each, including two songs and their movement instructions. There are three songs in all, because the title song, “Mutaveijarit” (or “The Mud Mates”) is part of both tracks (see Table
2). The third video includes all songs, with movements but without any verbal instructions, and it lasts about 12 min.
Table 2
Details of the music used for the movement-to-music DVD
Video 1: Mutaveijarit ja karibialainen kala (10 minutes) |
”Mutaveijarit” | Eeva-Leena Pokela and Mutaveijarit | Children’s rock | 94 | 34.6 vs. 33.7 |
“Karibialainen kala” | Aili Järvelä | Children’s Latin | 128 | 34.0 vs. 31.9 |
Video 2: Kuraa ja mutaa (10 minutes) |
”Kuravelli” | Miia Reko and Mutaveijarit | Children’s folk | 124 | 32.5 vs. 31.4 |
“Mutaveijarit” | Eeva-Leena Pokela and Mutaveijarit | Children’s rock | 94 | |
Video 3: Mutaveijarit kooste (12 minutes) |
”Mutaveijarit”,”Karibialainen kala”,”Kuravelli”, and again”Mutaveijarit” |
To rate the motivational qualities of the three songs, a panel of eight physiotherapists (all female and comparable to the adult intervention participants in age, race, and cultural background) assessed each song by using the BMRI-2 [
28,
29]. Another reason for pre-testing was to find out the influence of visual stimuli on the responses to the music. The BMRI-2 was translated into Finnish by investigators involved in the present study.
Each song was rated with a one number from 1 (“Strongly disagree”) and 7 (“Strongly agree”) for six statements about how much the characteristic features of the music would motivate a person during exercise. The range of total scores is 6–42, with scores below 24 indicating low motivational quality or an oudeterous (neutral) nature, those in the middle range (24–35) representing moderate motivation, and scores over 35 denoting highly motivating material [
28].
The members of the video group (
n = 4, mean age 41 years, SD 16.2 years) first watched the DVD and assessed all three songs separately, using the BMRI-2. Then they listened to the music only (without video) and rated the motivational quality of each song. The music group (
n = 4, mean age 42.8 years, SD 15.8 years) assessed the motivational qualities of the songs first, then watched the DVD and appraised the music and video content together. In addition, both groups moved to the DVD and rated the motivational qualities of the music during movement. Music and video together received higher motivation ratings than did the music alone, from both groups (see Table
2).
The movement program
The exercises in the videos are based on PA recommendations [
5] and include exercises to improve or maintain aerobic fitness, muscle strength, balance, and coordination (including motor and rhythm coordination) [
31]. All three songs begin with the Mud Mates getting up from a sofa. Each song has its own movements, which are performed to the beat of the music. The videos serve to encourage and motivate mother and child to exercise together and allow them to choose suitable movements for themselves from one to three variations.
The first song, “Mutaveijarit”, is accompanied by movements to improve aerobic fitness (walking, jumping, stepping, and shaking one’s whole body), postural balance (standing on one leg), and motor coordination (pelvic and midriff control, and agility). The second song, “Karibialainen kala”, involves movements to improve dynamic balance (moving the center of gravity to the edge of the area of support) and motor coordination (Caribbean dance movements such as swaying from side to side and making stepping motions). The third song, “Kuravelli”, entails movements to improve muscle strength (squats and lunges) and aerobic fitness (walking, jumping, and the side gallop). The last song, “Mutaveijarit”, (the same as the first) combines movement elements from all three previous songs.
The measurements and exercise diaries
Objective measurement of the SB and PA of the mothers and children will be conducted in the first, second and eighth weeks of the intervention via accelerometer use during waking hours. The mothers’ body weight will be measured at baseline.
Participants will be instructed to complete exercise diaries for the time for which they wear the accelerometers. The mothers will be asked to indicate their working hours and actual exercise, such as walking, jogging, running, swimming, biking, gym workouts, and dancing in the diaries. Start and end time of the exercise are to be filled in. Also, the participants will be instructed to assess the perceived exertion their exercise involves numerically: 1 = light PA, with no shortness of breath or sweating at all; 2 = moderate PA, with some shortness of breath or sweating; and 3 = vigorous PA, indicating heavy breathing or increased sweating. If more than one type of exercise is performed in the course of a day, the participants are to include all of these in the diaries. Mothers are asked to record the child’s exercise time at daycare or school and at home, and the time spent in PA, in the children’s diaries.
Questionnaires
Information on participants’ background, PA, screen time, motivation to exercise, and self-reported height and weight, along with information on quality of life, will be collected at the baseline by means of the same questionnaires used for the NELLI five-year follow-up study (based on original and one-year follow-up questionnaires for the NELLI cohort). At two weeks after baseline, information on PA, screen time, self-reported weight, musical background, and motivation to exercise by means of a movement-to-music video program will be collected for the intervention group. At the eighth week after baseline, information on PA, screen time, motivation to exercise, and (self-reported) weight will be collected from all participants. Information on motivation to exercise by using the movement-to-music video program will be collected from the intervention group. Information on the children’s PA and screen time will be collected at baseline and the second and eighth week after baseline via questionnaires.
The information on participants’ background includes data on socioeconomic status, smoking, and height and weight. The participants of the intervention group will be asked for information on the mother’s musical background.
Mothers’ earlier PA will be examined at baseline via a leisure-time physical activity (LTPA) questionnaire, addressing the amount, duration, and intensity of PA within a typical week over the previous year. The validity and reliability of these questions have been examined previously [
32]. The questionnaire on participants’ current PA and time spent in a sitting position in various contexts (on both weekdays and weekends) is the same as that utilized in the national Health 2011 Survey [
33] and FINRISKI 2011 Study [
34] in Finland, intended to ascertain how fully people meet the PA recommendations and how much they tend to sit. The questionnaire on the child’s typical exercise and screen time is based on the same questionnaire used in the Finnish project on health monitoring among children and young people (LATE) [
35], with a protocol reported upon earlier [
36]. There are separate questions on outside activities, exercises, and screen time. Both weekdays and weekends are covered. Responses to questionnaire items on current PA and on time spent in a sitting position and screen time will be examined at baseline and after week 8 for all participants, as will the figures for just after the second week for the intervention group.
The instrument examining motivation to exercise is based on the Finnish version [
37] of the Enjoyment in Sport (EIS) questionnaire [
38] and also addresses some factors motivating exercise [
39]. Investigators involved in the present study modified the questions to be appropriate for exercising with children, for example, the statement “I like exercising” was changed to “I like exercising with a child.” Motivation and intention to encourage the child to perform PA will be examined by means of a short version of a theory of planned behavior (TPB) questionnaire [
40]. In the first phase, this questionnaire was developed on the basis of the TPB manual instructions at University of Jyväskylä, Finland. In the second phase, it was pre-tested for clarity of language and suitability for the local culture by five experts in various relevant fields (physical education, exercise physiology, kinesiology, and health science). In the third phase, items with low reliability indices were excluded on the basis of pilot data collection from around 100 parents of 4–7-year-old children [
41]. The final version of the TPB short form used in the present study is composed of elements on behavior, intention, attitudes to the behavior, and perceived control over the behavior. Motivation questions will be evaluated at baseline and after the eighth week for all participants and, in addition, for the intervention group after week 2.
The relationship between SB or PA and quality of life, depression, and anxiety is also of interest. Assessments of quality of life, depression, anxiety, and work ability will be performed via Finnish versions of the validated indicator. Quality of life will be assessed via the 15D instrument [
42], depression via Beck’s Depression Inventory (BDI) [
43], and anxiety by means of the State Anxiety Inventory (SAI) [
44]. A visual analogue scale (VAS) will be used in the assessment of perceived health and an 11-point Likert scale for work ability. The 15D has 15 separate items: ability to be physically active, vision, hearing, breathing, sleeping, eating, communicating, elimination, normal functions, mental health, signs and symptoms, depression, anxiety, vitality, and sexuality. The BDI, in turn, is based on 21 distinct items for measuring the severity of depression in terms of a list of four statements. The SAI, a sub-scale of the State-Trait Anxiety Inventory (STAI), has 20 items for assessing “how I feel right now” on a four-point scale (“not at all” – “somewhat” – “moderately so” – “very much so”). Ten of the 20 statements typify presence and the other 10 absence of anxiety. Perceived health is an important factor when one wishes to predict functional capacity and health [
45], and it will be measured via a VAS. Perceived work ability at the moment, relative to lifetime best, will be evaluated on an 11-point Likert scale, where 0 = total disability and, 10 = work ability at its best ever. Perceived deficiency of work ability in midlife is associated with accelerated weakening in health and functioning in later life [
46]. Quality of life, depression, anxiety, perceived health, and work ability assessment will be evaluated for all participants at baseline.
In addition, there is a questionnaire for subgroup analysis, made up of questions for the intervention group. The items on mother’s musical background include questions about prior singing, playing of an instrument, dancing, and listening to music. The questionnaire on the motivational quality of the music is based on the BMRI-2. In this, the music will be rated on a scale of 1 (for strong disagreement) to 7 (for strong agreement) with each of six statements about how much the characteristic features of the music would motivate a person during exercise [
29]. Experiences of use of the movement-to-music video program, factors (other than music) motivating exercise, and perceived changes in PA will be assessed via a questionnaire that was developed by investigators working on the present study. Participants will rate their experiences of use of the video on a scale of 1 (“Hard”) to 3 (“Easy”). Factors motivating exercise (the video’s characters, movements, and ambience and exercising with the child) will be rated on a scale of 1 (for “Strongly disagree”) to 7 (for “Strongly agree”). Perceived changes in PA will be rated between 1 (“Much less than earlier”) and 5 (“Much more than earlier”). In addition, participants will be asked about their actual activity while watching the video, including how well they performed the exercises in accordance with the video instructions, and about perceived personal shortcomings in physical fitness during completion of the video exercises. The questionnaires for subgroups were pre-tested by a group of eight physiotherapists and piloted in a separate pilot study. Items on mother’s musical background and BMRI-2 scores will be evaluated after second week, other questions after weeks 2 and 8.